1. Field of the Invention
The invention relates to a system for the supply of forge-proof information about an article and, in particular, to a system having two elements associated with unique information, both elements being connected to the article.
2. Related Art
Machine readable bar codes comprising a plurality of line-shaped white and black areas are being used increasingly as replacements for concrete price markings on articles in department stores and warehouses. Bar codes are also being used to check in items of luggage at airports, for example.
A bar code contains a plurality of information contents. One bar code developed by the UCC (Uniform Code Council) is referred to as the UPC (Universal Product Code). This code contains information about the manufacturer of the accordingly marked article as well as a special line arrangement that enables the article and/or price information belonging to the article to be retrieved from a storage device in a clearly defined manner. Furthermore, the code usually contains at least one check character which ensures that the code has been correctly read by the scanner (bar code reader). This bar code reader is conventionally a laser scanner.
Bar codes are easy to forge. This is done most easily by photocopying the bar code, assigning the bar code a lower or higher price according to the particular purpose. Marking with a higher price is meaningful, for example, when the deposit is scanned in automatic deposit dispensers and a credit is booked automatically.
Department stores and warehouses are making increasing use of security elements for electronic article surveillance in addition to the above mentioned bar codes. Inventory losses can be reduced considerably by using security elements of this type.
From published international application WO 97/04338 there is also known a security element which in addition to performing a security function is capable of making an article marked with the security element identifiable, that is, the security element used in the field of electronic article surveillance contains equally a defined information content.
The known security element is constructed as follows. It consists of a first magnetic material of high permeability and low coercive force and a second material that can be permanently magnetized. The second material is differently magnetized in different zones. As a result of this different magnetization in different zones, the security element emits a characteristic signal in the field of an electromagnetic interrogating device, allowing unmistakable conclusions to be drawn about the secured article.
Proceeding from the state-of-the-art, it is an object of the present invention to provide an element with a defined information content so that it cannot be forged.
This object is accomplished in that the first and second information contents (I1, I2) of the two elements are linked by a logic connection.
According to an advantageous aspect of the system of the present invention, the first element is a security element which emits a characteristic signal in the field of an electronic interrogating device. It is equally possible, however, for the first element to be a bar code or some other element, provided this element is able to supply an unambiguous information content.
In cases where the first element is a security element for electronic article surveillance, the security element has in an advantageous further aspect a characteristic signal shape that enables the assigned article to be identified unambiguously. Alternatively, the characteristic signal can lie within a clearly defined frequency range. It is possible furthermore to make use of all possibilities capable of assigning a defined information content to the security element.
In an advantageous further aspect of the system of the present invention, it is proposed for the second element to be a bar code or some other machine readable code.
As soon as the characteristic signal of the electronic security element and that of the bar code have been entered into an input device, the information contents held in a storage unit and assigned to the particular signal are retrieved. The first and second information contents (I1, I2) of the two elements are a, compared with each other in a computing unit. It is only if the two information contents are in a predefined relationship to each other that the bar code""s price information, for example, will be accepted as correct.
The system of the present invention is suitable for use in an automatic deposit dispenser, for example. In this case, the 10 information content of the first element, meaning the security element, enables an unambiguous statement to be made as to whether the article involved is disposable or returnable; if the characteristic signal shape reveals it to be a returnable article, the second element supplies the information about what type of returnable article is involved.
Using the second element, meaning the code, a check is then carried out to see whether the information contents of the first and the second element, meaning the security element and the code, are linked by a predetermined logic connective. The article is not treated as returnable until the predetermined logic connective is confirmed.
In accordance with an advantageous further aspect of the system of the present invention, this logic connection is created by having the characteristic signal display a defined shape and having this shape serve as proof of the code""s authenticity. This special shape is identifiable from the number of peaks, from the shape of the individual peaks, or from the frequency range in which the characteristic signal lies.
To make it impossible for the elements to be manipulated, an advantageous further aspect of the system of the present invention provides for the first element, meaning the security element, to be integrated in the article or its packaging in such a way that it cannot be recognized, from the outside. This prevents the interaction of the two elements being destroyed by removal or replacement of the security element.